低浓度CO气体的OPO-CARS测量方法研究

Study on Test of Low Concentration CO Gas with OPO-CARS

利用相干反斯托克斯拉曼光谱 ( CARS)技术 ,根据在低浓度时极化率的共振项对非共振项的调制大小 (调制度 )与被测气体浓度的关系 ,提出了微量气体浓度的测量方法 ,建立了共振极化率的调制度与被测气体浓度、温度之间关系 ,验证了数量关系式的正确性 ,其结果是理论值与实验值在低浓度范围内的偏差不超过 4.5 %。并实测了酒精火焰中不同位置处的 CO浓度 。

Using Coherent anti Stokes Raman Spectroscopy(CARS),a method is presented to measure the low concentration species in other species,according to the relation between species concentration and modulated degree,which of resonant susceptibility to non resonant susceptibility in low concentration,.A formula is given between modulated degree of resonant susceptibility,gas concentration and temperature,which is verified by experiment.The CO concentration is measured in different position of alcohol frame.The error,between theoretical value and experimental value,is lowered to 4.5%.Influence of temperature on testing is discussed.